The present invention relates to a crankshaft bearing for a reciprocating, piston-type, internal combustion engine having multiple cylinders arranged in a housing made of a light metal alloy, including bearing bores for crank pins of a crankshaft and first and second bearing sections with first and second thrust bearings running across a longitudinal plane of the crankshaft on both sides of a bearing parting plane, said second thrust bearings being part of a crankshaft bearing bridge connected to a crankcase.
A crankshaft bearing for an internal combustion engine is shown in DE 34 26 208 C1. A crankcase and a bearing crown attached thereto, forming part of a crankshaft bearing bridge, are made of a light metal alloy. The bearing crowns are configured as a cast sheathing for ferrometallic cores, with the cores contributing to an increase in rigidity of the bearing crowns and/or the crankshaft bearing bridge and also reducing the noise-producing bearing play between the bearing bore and the bearing pin of a crankshaft.
DE 43 30 565 C1 describes a crankshaft bearing which is provided in a housing made of a light metal alloy in an internal combustion engine and includes a bearing bore for a crank pin. With this crankshaft bearing, a device is effective in reducing the increased bearing play between the bearing bore and crank pin. This device is configured as a ring-like compensator element which operates between the bearing bore and the crank pin and is made of a material having a relatively large coefficient of thermal expansion.
Furthermore, bearing bridges for internal combustion engines are described in DE 22 57 651 and EP 0 038 560, where neighboring thrust bearings are supported only by longitudinal walls and/or longitudinal side members.
An object of the present invention is to provide a crankshaft bearing bridge for an internal combustion engine which is characterized by a high strength and low-noise bearing of the crankshaft with a simple design.
According to the present invention, this object can be achieved by providing that at least a portion of neighboring bore halves of the second thrust bearings of the crank shaft bearing bridge having bearing bores are supported by connecting elements, and the second thrust bearings of the internal combustion engine open into longitudinal walls of the crankshaft bearing bridge with local widened areas in between.
The main advantages achieved with the present invention include the fact that, due to the particular structural configuration of the crankshaft bearing bridge made of a light metal alloy, the bridge is advantageously and especially rigid and strong with a low weight. The rigid frame structure with the connecting elements between the thrust bearings of the crankshaft bearing bridge can be implemented with a low complexity without additional equipment that would cause bimetal effects. The connecting elements and/or the walls forming them not only act as an oil plane but also these connecting elements are arranged in such a way that they result in relatively large ventilation cross-sections, thereby reducing pump losses. Furthermore, this frame structure in combination with the thermally treated thrust bearings made of the light metal alloy contributes to a uniform, controlled increase in the bearing bore over the operating temperature of the internal combustion engine, i.e., this at least reduces the ovalization of said bearing bore, which would otherwise be the case.